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  <div class="section" id="introduction">
<h1>Introduction<a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h1>
<p>This is the reference guide for PyQt 4.9.1.  PyQt v4 is a set of
<a class="reference external" href="http://www.python.org">Python</a> bindings for v4 of the Qt application
framework from <a class="reference external" href="http://qt.nokia.com">Nokia</a>.</p>
<p>There is a separate <a class="reference external" href="classes.html">PyQt Class Reference</a>.</p>
<p>Qt is a set of C++ libraries and development tools that includes platform
independent abstractions for graphical user interfaces, networking, threads,
Unicode, regular expressions, SQL databases, SVG, OpenGL, XML, and user and
application settings.  PyQt implements 440 of these classes as a set of
Python modules.</p>
<p>PyQt supports the Windows, Linux, UNIX and MacOS/X platforms.</p>
<p>PyQt does not include Qt itself - you must obtain it separately.</p>
<p>The homepage for PyQt is <a class="reference external" href="http://www.riverbankcomputing.com/software/pyqt/">http://www.riverbankcomputing.com/software/pyqt/</a>.
Here you will always find the latest stable version, current development
snapshots, and the latest version of this documentation.</p>
<p>PyQt is built using the <a class="reference external" href="http://www.riverbankcomputing.com/software/sip/">SIP bindings generator</a>.  SIP must be installed in
order to build and use PyQt.</p>
<p>Earlier versions of Qt are supported by PyQt v3.</p>
<div class="section" id="license">
<h2>License<a class="headerlink" href="#license" title="Permalink to this headline">¶</a></h2>
<p>PyQt is licensed on all platforms under a commercial license, the GPL v2 and
the GPL v3.  Your PyQt license must be compatible with your Qt license.  If
you use the GPL versions then your own code must also use a compatible
license.</p>
<p>PyQt, unlike Qt, is not available under the LGPL.</p>
<p>You can purchase a commercial PyQt license <a class="reference external" href="http://www.riverbankcomputing.com/commercial/buy">here</a>.</p>
</div>
<div class="section" id="pyqt-components">
<h2>PyQt Components<a class="headerlink" href="#pyqt-components" title="Permalink to this headline">¶</a></h2>
<p>PyQt comprises a number of different components.  First of all there are a
number of Python extension modules.  These are all installed in the
<tt class="xref py py-mod docutils literal"><span class="pre">PyQt4</span></tt> Python package.</p>
<ul class="simple">
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtCore</span></tt> module.  This contains the core non-GUI classes,
including the event loop and Qt&#8217;s signal and slot mechanism.  It also
includes platform independent abstractions for Unicode, threads, mapped
files, shared memory, regular expressions, and user and application settings.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtGui</span></tt> module.  This contains the majority of the GUI
classes.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtHelp</span></tt> module.  This contains classes for creating and
viewing searchable documentation.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtNetwork</span></tt> module.  This module contains classes for writing
UDP and TCP clients and servers.  It includes classes that implement FTP and
HTTP clients and support DNS lookups.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtOpenGL</span></tt> module.  This module contains classes that enable
the use of OpenGL in rendering 3D graphics in PyQt applications.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtScript</span></tt> module.  This module contains classes that enable
PyQt applications to be scripted using Qt&#8217;s JavaScript interpreter.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtScriptTools</span></tt> module.  This module contains classes that
contain additional components (e.g. a debugger) that are used with Qt&#8217;s
JavaScript interpreter.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtSql</span></tt> module.  This module contains classes that integrate
with SQL databases.  It includes editable data models for database tables
that can be used with GUI classes.  It also includes an implementation of
<a class="reference external" href="http://www.sqlite.org">SQLite</a>.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtSvg</span></tt> module.  This module contains classes for displaying
the contents of SVG files.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtTest</span></tt> module.  This module contains functions that enable
unit testing of PyQt applications.  (PyQt does not implement the complete Qt
unit test framework.  Instead it assumes that the standard Python unit test
framework will be used and implements those functions that simulate a user
interacting with a GUI.)</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtWebKit</span></tt> module.  This module implements a web browser
engine based on the WebKit open source browser engine.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtXml</span></tt> module.  This module contains classes that implement
SAX and DOM interfaces to Qt&#8217;s XML parser.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtXmlPatterns</span></tt> module.  This module contains classes that
implement XQuery and XPath support for XML and custom data models.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">phonon</span></tt> module.  This module contains classes that implement
a cross-platform multimedia framework that enables the use of audio and video
content in PyQt applications.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtDBus</span></tt> module.  This Unix-only module provides classes that
support Inter-Process Communication using the D-Bus protocol.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtDeclarative</span></tt> module.  This module provides a declarative
framework for building highly dynamic, custom user interfaces using QML.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtMultimedia</span></tt> module.  This module provides low-level
multimedia functionality.  Application developers would normally use the
<tt class="xref py py-mod docutils literal"><span class="pre">phonon</span></tt> module.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtAssistant</span></tt> module.  This module contains classes that
allow Qt Assistant to be integrated with a PyQt application to provide online
help.  This module is not available with Qt v4.7 and later - use the
<tt class="xref py py-mod docutils literal"><span class="pre">QtHelp</span></tt> module instead.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QtDesigner</span></tt> module.  This module contains classes that allow
Qt Designer to be extended using PyQt.  See <a class="reference internal" href="designer.html#ref-designer-plugins"><em>Writing Qt Designer Plugins</em></a> for a
full description of how to do this.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">QAxContainer</span></tt> module.  This Windows-only module contains
classes that allow access to ActiveX controls and COM objects.</li>
<li>The <tt class="xref py py-mod docutils literal"><span class="pre">Qt</span></tt> module.  This module consolidates the classes contained
in all of the modules described above into a single module.  This has the
advantage that you don&#8217;t have to worry about which underlying module contains
a particular class.  It has the disadvantage that it loads the whole of the
Qt framework, thereby increasing the memory footprint of an application.
Whether you use this consolidated module, or the individual component modules
is down to personal taste.</li>
<li>The <a class="reference external" href="http://www.freedesktop.org/wiki/Software_2fdbus">DBus</a> support
module is installed as <tt class="xref py py-mod docutils literal"><span class="pre">dbus.mainloop.qt</span></tt>.  This module provides support
for the Qt event loop in the same way that the <tt class="xref py py-mod docutils literal"><span class="pre">dbus.mainloop.glib</span></tt>
included with the standard <tt class="docutils literal"><span class="pre">dbus-python</span></tt> bindings package provides support
for the GLib event loop.  The API is described in <a class="reference internal" href="dbus.html#ref-dbus"><em>The Legacy DBus Support Module</em></a>.  It is
only available for PyQt for X11 and only if the <tt class="docutils literal"><span class="pre">dbus-python</span></tt> v0.80 (or
later) bindings package is installed.  There are no plans for <tt class="docutils literal"><span class="pre">dbus-python</span></tt>
to be ported to Python v3 and so it is recommended that new applications use
the <tt class="xref py py-mod docutils literal"><span class="pre">QtDBus</span></tt> module instead.</li>
<li>The <a class="reference internal" href="designer.html#module-PyQt4.uic" title="PyQt4.uic"><tt class="xref py py-mod docutils literal"><span class="pre">uic</span></tt></a> module.  This module contains classes for handling the
<tt class="docutils literal"><span class="pre">.ui</span></tt> files created by Qt Designer that describe the whole or part of a
graphical user interface.  It includes classes that load a <tt class="docutils literal"><span class="pre">.ui</span></tt> file and
render it directly, and classes that generate Python code from a <tt class="docutils literal"><span class="pre">.ui</span></tt> file
for later execution.</li>
<li>The <a class="reference internal" href="build_system.html#module-PyQt4.pyqtconfig" title="PyQt4.pyqtconfig"><tt class="xref py py-mod docutils literal"><span class="pre">pyqtconfig</span></tt></a> module is an extention of the SIP build system
and is created when PyQt is configured.  It encapsulates all the necessary
information about your Qt installation and makes it easier to write
installation scripts for bindings built on top of PyQt.  It is covered in
detail in <a class="reference internal" href="build_system.html#ref-build-system"><em>The PyQt Build System</em></a>.</li>
</ul>
<p>PyQt also contains a number of utility programs.</p>
<ul>
<li><p class="first"><strong class="program">pyuic4</strong> corresponds to the Qt <strong class="program">uic</strong> utility.  It converts
GUIs created using Qt Designer to Python code.</p>
</li>
<li><p class="first"><strong class="program">pyrcc4</strong> corresponds to the Qt <strong class="program">rcc</strong> utility.  It embeds
arbitrary resources (eg. icons, images, translation files) described by a
resource collection file in a Python module.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">It will only be included if your copy of Qt includes the XML module.</p>
</div>
</li>
<li><p class="first"><strong class="program">pylupdate4</strong> corresponds to the Qt <strong class="program">lupdate</strong> utility.  It
extracts all of the translatable strings from Python code and creates or
updates <tt class="docutils literal"><span class="pre">.ts</span></tt> translation files.  These are then used by Qt Linguist to
manage the translation of those strings.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">It will only be included if your copy of Qt includes the XML module.</p>
</div>
</li>
</ul>
<p>When PyQt is configured a file called <tt class="file docutils literal"><span class="pre">PyQt4.api</span></tt> is generated.  This can
be used by the QScintilla editor component (at
<a class="reference external" href="http://www.riverbankcomputing.com/software/qscintilla/">http://www.riverbankcomputing.com/software/qscintilla/</a>) to enable the use of
auto-completion and call tips when editing PyQt code.  The API file is
installed automatically if QScintilla is already installed.</p>
<p>PyQt includes a large number of examples.  These are ports to Python of many
of the C++ examples provided with Qt.  They can be found in the
<tt class="file docutils literal"><span class="pre">examples</span></tt> directory.</p>
<p>Finally, PyQt contains the <tt class="docutils literal"><span class="pre">.sip</span></tt> files used by SIP to generate PyQt
itself.  These can be used by developers of bindings of other Qt based class
libraries - for example <a class="reference external" href="http://pyqwt.sourceforge.net/">PyQwt and PyQwt3D</a>.</p>
</div>
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  <h3><a href="index.html">Table Of Contents</a></h3>
  <ul>
<li><a class="reference internal" href="#">Introduction</a><ul>
<li><a class="reference internal" href="#license">License</a></li>
<li><a class="reference internal" href="#pyqt-components">PyQt Components</a></li>
</ul>
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